[Skiboot] [PATCH v2] xive/p9: Enforce thread enablement

[Cédric Le Goater]

Make sure that the enablement has completed to guarantee that the TIMA
accesses will see the latest state of the enable register.

Signed-off-by: Cédric Le Goater <clg at kaod.org>
---
 hw/xive.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/hw/xive.c b/hw/xive.c
index 8d6095c02e7e..fcb5559282cb 100644
--- a/hw/xive.c
+++ b/hw/xive.c
@@ -2741,6 +2741,7 @@ static void xive_reset_enable_thread(struct cpu_thread *c)
 	struct proc_chip *chip = get_chip(c->chip_id);
 	struct xive *x = chip->xive;
 	uint32_t fc, bit;
+	uint64_t enable;
 
 	/* Get fused core number */
 	fc = (c->pir >> 3) & 0xf;
@@ -2752,9 +2753,16 @@ static void xive_reset_enable_thread(struct cpu_thread *c)
 	if (fc < 8) {
 		xive_regw(x, PC_THREAD_EN_REG0_CLR, PPC_BIT(bit));
 		xive_regw(x, PC_THREAD_EN_REG0_SET, PPC_BIT(bit));
+
+		enable = xive_regr(x, PC_THREAD_EN_REG0);
+		if (!(enable & PPC_BIT(bit)))
+			xive_cpu_err(c, "Failed to enable thread\n");
 	} else {
 		xive_regw(x, PC_THREAD_EN_REG1_CLR, PPC_BIT(bit));
 		xive_regw(x, PC_THREAD_EN_REG1_SET, PPC_BIT(bit));
+		enable = xive_regr(x, PC_THREAD_EN_REG1);
+		if (!(enable & PPC_BIT(bit)))
+			xive_cpu_err(c, "Failed to enable thread\n");
 	}
 }
 
-- 
2.25.4